Diseases & Conditions
The common name for rubella, this viral infection is not very similar to MEASLES, although it also causes a rash on the face, trunk, and limbs. Rubella, which causes a mild illness in children, is really serious only when contracted by pregnant women in the early months of gestation. During this time, there is a chance the virus will infect the fetus, which can lead to a range of serious birth defects known as rubella syndrome.
Although rubella was once found throughout the world, it is now much less common in most developed countries because of successful vaccination programs. The United States has tried to eradicate the disease by vaccinating all school-age children; in 1969 when the vaccine became available, at least 60,000 Americans had rubella. By 1993 the number had dropped to 192.
Rubella is caused by rubella virus that is transmitted by particles in the air when an infected person coughs or sneezes. It can also be transmitted on contaminated objects, where the virus can survive for a short period of time on tissues, doorknobs, phones, and so on. It infects only humans.
Before the development of the vaccine, rubella was common in spring and winter and peaked every six to nine years. There were huge rubella epidemics in the United States in 1935, 1943, and 1964.
In the past, the infection usually affected youngsters between ages six and 12 with a rash beginning on the face and spreading downward and outward to arms and legs. The rash typically runs together to make large patches, but it does not itch. It lasts for a few days, with a slight fever (less than 101°F.) and enlarged lymph nodes; some children may have a mild cough, sore throat, or runny nose before the rash appears. Sometimes the entire infection comes and goes without notice; at least 30 percent of children with rubella have no symptoms at all, although they are infectious to others.
Adolescents may have slightly more pronounced symptoms, including headaches, fever, body aches, eye infections, or a runny nose about one to ﬁve days before the rash. Swollen glands in the neck and ear typically appear seven to 10 days before the rash. The virus may be transmitted from a few days before the symptoms appear until a day after symptoms fade.
Incubation period ranges from 14 to 23 days; the average is 16 to 18 days.
Rubella may be confused with other conditions characterized by rashes, such as SCARLET FEVER or drug allergy.
A lab test to conﬁrm rubella is important, since the symptoms can be so mild they may be overlooked or mistaken for something else. Blood tests are available that reveal rubella immunity or an active rubella infection. If a person has been vaccinated, the blood test will show that the person is immune.
There is no speciﬁc treatment for rubella, although acetaminophen may reduce the fever.
Congenital rubella is the most serious complication of rubella infection, since it can cause fetal death or miscarriage. The risk is highest when the pregnant woman is infected in the ﬁrst 12 weeks of pregnancy (miscarriage rate is as high as 85 percent during this time). At 14 to 16 weeks, the risk drops to just 10 to 24 percent, and after 20 weeks the risk is almost nonexistent.
Infants who survive infection in the womb may be born with a variety of birth defects, including deafness, eye problems (including blindness), ear defects, MENTAL RETARDATION, growth retardation, and bleeding disorders.
Any child with rubella must be kept at home until well past the infectious stage; babies born with rubella have the virus in their nose, throat, and urine for as long as a year.
Vaccination can provide long-lasting immunity. There is not usually any reaction to the vaccine, which is produced with a live virus that offers complete prevention to more than 95 percent of those who receive it. Rubella infection itself also provides immunity.
The recommended vaccine for all infants in the United States, is the MMR (measles, mumps, rubella), which is not effective when given earlier than 12 months because the baby may have maternal antibodies that will interfere with the vaccine’s action. Therefore, the ﬁrst dose of MMR is typically given to infants between 12 to 15 months; a booster is given at age four to six, before the child starts school. Older children who missed these shots should receive one dose of MMR.
Anyone who is not sure of having received the vaccine or having rubella should be vaccinated; there is no risk to receiving the vaccine if a person is already immune.
Children with a high fever or a severe allergy to neomycin should not be given the vaccine. There is no penicillin in rubella vaccine, and it is safe for those allergic to eggs.